<?xml version="1.0"?>
<?xml-stylesheet href="chrome://global/skin" type="text/css"?>

<window id="321671Test"
        xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
        width="600"
        height="600"
        onload="setTimeout(nextTest,0);"
        title="bug 321671 test">

  <script type="application/javascript" src= "chrome://mochikit/content/chrome-harness.js" />
  <script type="application/javascript" src="docshell_helpers.js" />
  <script type="application/javascript"><![CDATA[
  
    // Define the generator-iterator for the tests.
    var tests = testIterator();
    
    // Maximum number of entries in the bfcache for this session history.
    // This number is hardcoded in docshell code.  In the test, we'll
    // navigate through enough pages so that we hit one that's been
    // evicted from the bfcache because it's farther from the current
    // page than this number.
    const MAX_BFCACHE_PAGES = 3;

    ////
    // Execute the next test in the generator function.
    //
    function nextTest() {
      tests.next();
    }

    ////
    // Generator function for test steps for bug 321671:  Scroll position 
    // should be retained when moving backwards and forwards through pages 
    // when bfcache is enabled.
    //
    function testIterator()
    {
      // Variable to hold the scroll positions of the test pages.
      var scrollPositions = [];
      
      // Make sure bfcache is on.
      enableBFCache(true);
      
      // Load enough test pages that so the first one is evicted from the
      // bfcache, scroll down on each page, and save the 
      // current scroll position before continuing.  Verify that each
      // page we're navigating away from is initially put into the bfcache.
      for (var i = 0; i <= MAX_BFCACHE_PAGES + 1; i++) {
        doPageNavigation( {
           uri: "data:text/html,<html><head><title>bug321671 page" + (i + 1) + 
                "</title></head>" +
                "<body><table border='1' width='300' height='1000'>" + 
                "<tbody><tr><td>" +
                " page " + (i + 1) + ": foobar foobar foobar foobar " +
                "</td></tr></tbody></table> " +
                "</body></html>",
           eventsToListenFor: ["pageshow", "pagehide"],
           expectedEvents: [ { type: "pagehide",
                               persisted: true,
                               title: i == 0 ? 
                                 undefined : "bug321671 page" + i },
                             { type: "pageshow", 
                               title: "bug321671 page" + (i + 1) } ],
           onNavComplete: nextTest 
          } );
        yield undefined;

        is(TestWindow.getWindow().scrollY, 0, 
          "Page initially has non-zero scrollY position");
        TestWindow.getWindow().scrollByLines(10 + (2*i));
        ok(TestWindow.getWindow().scrollY > 0,
          "Page has zero scrollY position after scrolling");
        scrollPositions[i] = TestWindow.getWindow().scrollY; 
      }
      
      // Go back to the first page, one page at a time.  For each 'back' 
      // action, verify that its vertical scroll position is restored 
      // correctly.  Verify that the last page in the sequence
      // does not come from the bfcache.  Again verify that all pages 
      // that we navigate away from are initially
      // stored in the bfcache.
      for (i = MAX_BFCACHE_PAGES + 1; i > 0; i--) {
        doPageNavigation( {
          back: true,
          eventsToListenFor: ["pageshow", "pagehide"],
          expectedEvents: [ { type: "pagehide",
                              title: "bug321671 page" + (i+1),
                              persisted: true }, 
                            { type: "pageshow", 
                              title: "bug321671 page" + i,
                              persisted: i > 1 } ],
          onNavComplete: nextTest
        } );
        yield undefined;
        
        is(TestWindow.getWindow().scrollY, scrollPositions[i-1], 
          "Scroll position not restored while going back!");
      }
      
      // Traverse history forward now, and verify scroll position is still 
      // restored.  Similar to the backward traversal, verify that all
      // but the last page in the sequence comes from the bfcache.  Also 
      // verify that all of the pages get stored in the bfcache when we 
      // navigate away from them.
      for (i = 1; i <= MAX_BFCACHE_PAGES + 1; i++) {
        doPageNavigation( {
          forward: true,
          eventsToListenFor: ["pageshow", "pagehide"],
          expectedEvents: [ { type: "pagehide", 
                              persisted: true, 
                              title: "bug321671 page" + i },
                            { type: "pageshow", 
                              persisted: i < MAX_BFCACHE_PAGES + 1,
                              title: "bug321671 page" + (i + 1) } ],
          onNavComplete: nextTest
        } );
        yield undefined;
        
        is(TestWindow.getWindow().scrollY, scrollPositions[i],
          "Scroll position not restored while going forward!");
      }
      
      // Tell the framework the test is finished.  Include the final 'yield' 
      // statement to prevent a StopIteration exception from being thrown.
      finish();
      yield undefined;
    }
    
  ]]></script>

  <browser type="content-primary" flex="1" id="content" src="about:blank"/>
</window>
